Population of 50m not a crowd-pleaser

The CSIRO has assessed a high-growth population policy as environmentally, socially and economically possible, but the idea of 50 million Australians found few advocates yesterday.

Environmentalists are unconvinced. The Premier, Bob Carr, is dismissive. Even the Australian Industry Group called 50 million an unfeasible "high five" figure.

Demographer Bob Birrell, director of the Centre for Population and Urban Research at Monash University, said 50 to 60 million was the CSIRO's best guess in the early '70s in a submission to the National Population inquiry.

"They said it was feasible but very unlikely given the risks, and since then we've discovered several extra risks," he said, noting the El Nino effect, global warming and dryland salinity.

"But the key value of the report is that it directly links implications of population growth - and growth in per capita affluence - to environmental indicators. Far too often in this debate the two are not linked.

Dr Birrell questioned the report's assumption that a bigger population would mean a transformed economy, saying the idea that this could pay for environmental repairs was a "leap in the dark". "Their suggestion is that if we had 30 million by 2050 maybe we'd have the population base to mix it in the global economy with high-tech, manufacturing and other services. That is a very hopeful scenario."

With 40 per cent of new migrants opting to live in Sydney, the city would become the focal point for resolving tensions between living standards and housing millions more residents.

Mr Carr rejected the high-growth model. "It would mean an unsustainable increase in population, particularly in the Sydney basin ... Our climate and soils won't allow for that sort of ... growth."

Heather Ridout, the deputy chief executive of the Australian Industry Group, offered support for a net immigration intake of 110,000 a year. "We should aim for 25 million by 2050," she said. "I think 50 million [by 2100] is an ambitious target and it's clear from the CSIRO report that it does involve trading off a number of environmental issues which I think, from a business perspective, may not be politically feasible."